Question

2 A 40 W bulb produces light of wavelength 620 mm
with 80% of effiuency. The number of photons
emitted by the bulb in 20 second are
(1ev= 1.6×10^-19J,HC=12400ev

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Answer 1

Answer:

A bulb of 40W is producing a light of wavelength 620 nm with 80% of efficiency. Then the number of photons emitted by the bulb in 20 seconds are:(1eV = 1. 6×10−19 J, hc = 12400 eV )